It's a module, not a package.

ftobia · ftobia · commit 18e2bfb3143e · 2014-03-16T21:08:35.000-04:00
diff --git a/setup.py b/setup.py
@@ -10,5 +10,5 @@
     author='Frank Tobia',
     author_email='frank.tobia@gmail.com',
     url='https://github.com/ftobia/pytest-ordering',
-    packages=['pytest_ordering'],
+    py_modules=['pytest_ordering'],
 )

Original file line number	Diff line number	Diff line change
`@@ -10,5 +10,5 @@`
`10`	`10`	`author='Frank Tobia',`
`11`	`11`	`author_email='[email protected]',`
`12`	`12`	`url='https://github.com/ftobia/pytest-ordering',`
`13`		`- packages=['pytest_ordering'],`
	`13`	`+ py_modules=['pytest_ordering'],`
`14`	`14`	`)`